1. Technical Field
The present invention relates to a robot and a robot control method.
2. Related Art
Traditionally, a robot or the like which moves a terminal device attached to a distal end of an arm to a desired position by rotation or the like of the arm and then causes the terminal device to operate at that position is known. For example, a member supplying and removing device which has a gripping terminal and supplies and removes a worked member to and from a working device, a painting robot having a painting terminal, a welding robot having a welding terminal and the like are known.
When driving a robot, a control method in which a rotational angle of a drive source such as a motor that drives an arm of the robot is measured and then the position or the like of a distal end side of the arm is controlled based on the measured angle information is used. However, since a transmission mechanism which transmits a driving force from the drive source to the arm and the arm are not rigid bodies, the transmission mechanism and the arm may deform. Because of this deformation of the transmission mechanism and the arm, there is a problem that the arm may vibrate. To address this problem, a technique in which an inertial sensor is attached to the distal end of the arm to measure the movement of the distal end and then angular velocity information obtained from the inertial sensor is used for control is proposed. JP-A-7-9374 discloses a multi-joint robot control method and a multi-joint robot in which the operation of an arm is controlled based on an output signal from an inertial sensor and thus a reduction in accuracy due to vibration can be prevented.
However, in the case of JP-A-7-9374, the output from the inertial sensor includes errors such as reference potential drift and noise. If such information is used to carry out control, there is a possibility that the control cannot be carried out correctly or there is a problem that stability may be lowered.